AuthenticationUtils

Added in 1.4.0-alpha03

public final class AuthenticationUtils

Summary

Public methods
static final @NonNull AuthenticationResultLauncher
registerForAuthenticationResult(
    @NonNull Fragment receiver,
    @NonNull Function0<Unit> onAuthFailedCallback,
    @NonNull AuthenticationResultCallback resultCallback
)

Register a request to start an authentication for result.
static final @NonNull AuthenticationResultLauncher
registerForAuthenticationResult(
    @NonNull FragmentActivity receiver,
    @NonNull Function0<Unit> onAuthFailedCallback,
    @NonNull AuthenticationResultCallback resultCallback
)

Register a request to start an authentication for result.

Public methods

registerForAuthenticationResult

public static final @NonNull AuthenticationResultLauncher registerForAuthenticationResult(
    @NonNull Fragment receiver,
    @NonNull Function0<Unit> onAuthFailedCallback,
    @NonNull AuthenticationResultCallback resultCallback
)

Register a request to start an authentication for result.

This must be called unconditionally, as part of initialization path, typically as a field initializer of an Fragment.

Note that if multiple calls to this method are made within a single Fragment or Activity, only the callback registered by the last invocation will be saved and receive authentication results. This can result in unexpected behavior if you intend to manage multiple independent authentication flows. It is strongly recommended to avoid multiple calls to this method in such scenarios.

import androidx.biometric.AuthenticationRequest
import androidx.biometric.AuthenticationRequest.Biometric
import androidx.biometric.AuthenticationRequest.Companion.biometricRequest
import androidx.biometric.AuthenticationResult
import androidx.biometric.PromptContentItemBulletedText
import androidx.biometric.registerForAuthenticationResult
import androidx.fragment.app.Fragment

class MyFragmentForCredentialOnlyAuth : Fragment() {
    val requestAuthentication =
        registerForAuthenticationResult(
            // Handle intermediate authentication failure, this is optional.
            onAuthFailedCallback = { Log.i(TAG, "onAuthenticationFailed, try again") }
        ) { result: AuthenticationResult ->
            when (result) {
                // Handle successful authentication
                is AuthenticationResult.Success -> {
                    Log.i(TAG, "onAuthenticationSucceeded with type" + result.authType)
                }
                // Handle authentication error, e.g. negative button click, user cancellation,
                // etc
                is AuthenticationResult.Error -> {
                    Log.i(
                        TAG,
                        "onAuthenticationError " + result.errorCode + " " + result.errString
                    )
                }
            }
        }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val authRequest =
            biometricRequest(
                title = "Title",
                authFallback = Biometric.Fallback.DeviceCredential,
            ) {
                setSubtitle("Subtitle")
                setContent(
                    AuthenticationRequest.BodyContent.VerticalList(
                        "Vertical list description",
                        listOf(
                            PromptContentItemBulletedText("test item1"),
                            PromptContentItemBulletedText("test item2")
                        )
                    )
                )
                setMinStrength(Biometric.Strength.Class3(/*optional: cryptoObject*/ ))
                setIsConfirmationRequired(true)
            }

        Button(context).setOnClickListener { requestAuthentication.launch(authRequest) }
    }
}
Parameters
@NonNull Function0<Unit> onAuthFailedCallback

the optional callback to be called on the main thread when authentication fails intermediately. This is not a terminal auth result, and could happen multiple times.
@NonNull AuthenticationResultCallback resultCallback

the callback to be called on the main thread when authentication result is available
Returns
@NonNull AuthenticationResultLauncher

the launcher that can be used to start the authentication.

registerForAuthenticationResult

public static final @NonNull AuthenticationResultLauncher registerForAuthenticationResult(
    @NonNull FragmentActivity receiver,
    @NonNull Function0<Unit> onAuthFailedCallback,
    @NonNull AuthenticationResultCallback resultCallback
)

Register a request to start an authentication for result.

This must be called unconditionally, as part of initialization path, typically as a field initializer of an Activity.

Note that if multiple calls to this method are made within a single Fragment or Activity, only the callback registered by the last invocation will be saved and receive authentication results. This can result in unexpected behavior if you intend to manage multiple independent authentication flows. It is strongly recommended to avoid multiple calls to this method in such scenarios.

import androidx.biometric.AuthenticationRequest
import androidx.biometric.AuthenticationRequest.Biometric
import androidx.biometric.AuthenticationRequest.Companion.biometricRequest
import androidx.biometric.AuthenticationResult
import androidx.biometric.PromptContentItemBulletedText
import androidx.biometric.registerForAuthenticationResult
import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentActivity

class MyActivityForBiometricAuth : FragmentActivity() {
    val requestAuthentication =
        registerForAuthenticationResult(
            // Handle intermediate authentication failure, this is optional.
            onAuthFailedCallback = { Log.i(TAG, "onAuthenticationFailed, try again") }
        ) { result: AuthenticationResult ->
            when (result) {
                // Handle successful authentication
                is AuthenticationResult.Success -> {
                    Log.i(TAG, "onAuthenticationSucceeded with type" + result.authType)
                }
                // Handle authentication error, e.g. negative button click, user cancellation,
                // etc
                is AuthenticationResult.Error -> {
                    Log.i(
                        TAG,
                        "onAuthenticationError " + result.errorCode + " " + result.errString
                    )
                }
            }
        }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val authRequest =
            biometricRequest(
                title = "Title",
                authFallback = Biometric.Fallback.DeviceCredential,
            ) {
                setSubtitle("Subtitle")
                setContent(
                    AuthenticationRequest.BodyContent.VerticalList(
                        "Vertical list description",
                        listOf(
                            PromptContentItemBulletedText("test item1"),
                            PromptContentItemBulletedText("test item2")
                        )
                    )
                )
                setMinStrength(Biometric.Strength.Class3(/*optional: cryptoObject*/ ))
                setIsConfirmationRequired(true)
            }

        Button(this).setOnClickListener { requestAuthentication.launch(authRequest) }
    }
}
Parameters
@NonNull Function0<Unit> onAuthFailedCallback

the optional callback to be called on the main thread when authentication fails intermediately. This is not a terminal auth result, so it could happen multiple times.
@NonNull AuthenticationResultCallback resultCallback

the callback to be called on the main thread when authentication result is available
Returns
@NonNull AuthenticationResultLauncher

the launcher that can be used to start the authentication.